Family: Aceraceae, maple family
Genus, species: Acer negundo
Leaves are pinnately compound, usually 3 leaflets per leaf, sometimes 5 or 7 leaflets per leaf. Leaflets are coarsely saw-toothed, sometimes lobed. Leaf petioles are often reddish.
Bark is light grayish-brown with narrow ridges, becomes more deeply furrowed on older trees.
Male and female flowers are on separate trees (dioecious). Flowers are small, yellowish-green, clustered. Male flowers are in upright clusters like an umbrella. Female flowers are in clusters on slender drooping stalks. Flowers emerge before leaves in spring.
Fruit is similar to helicopter-like fruits of sugar maple. Box elder fruits are more v-shaped compared to sugar maple fruits. Each fruit contains two seeds. Only female trees produce fruit.
Box elder lives in wet or moist soils along stream banks.
The common name, box elder, is based on the similarity of its wood to boxwood and the similarity of its leaves to elderberry.
The genus name, Acer, is from the Latin for "sharp," referring to the sharply pointed lobes on the leaves. The species name, negundo, is from a Sanskrit name, nirgundi, for a tree with leaves shaped like the box elder.